The Muslim Extremist group ISIS has already broadly threatened the United States for airstrikes against the group, killing two American journalists, and threatening to behead a third person, a British citizen, for the UK's participation in efforts to halt their growth.

However, its being reported that the group is now threatening employees of the social media site Twitter, which has been, albeit somewhat half-heartedly, engaged in the monitoring and closing down of the accounts of ISIS fighters.

The call for retribution against the online platform first came to light Sunday night in a series of tweets asking “lone wolves” cells in the U.S. and Europe to make Twitter employees the focus of their attacks.

The tweet, which has since been taken down and the originating account suspended by Twitter, when translated read:

#The_Concept_of_Lone_Wolf_Attacks The time has arrived to respond to Twitter’s management by directly attacking their employees and physically assassinating them!! Those who will carry this out are the sleepers cells of death.

Its been noted that Twitter and other social media outlets to recruit new members, brag of its activities and make hashtags trend. For the most part, Twitter either hasn't been willing to do anything about the tweets or just chosen to ignore them. But apparently, that is changing.

In the days following the release by ISIS (or ISIL as it also known) of the most recent video showing the beheading of an American reporter, James Foley, very little traffic on accounts attributed to ISIS followers could be found. Many experts attributed this silence to a crack down by Twitter on these accounts. But by Friday of last week, many of the questionable accounts reappeared under new names, showing support for ISIS, with some bragging about getting around Twitter's new security measures. Many were defending Foley's killing, pointing to "western hypocrisy" regarding "graphic violence."

Twitter has not publicly admitted to whether it is actually beefing up its security, but does state that its security team is investigating the legitimacy of the threats in conjunction with law enforcement officials.